President Trump tweeted on Thursday, announcing Pruitt's departure from the EPA. "General Sessions and I are friends and I have always said I want nothing more than to see him succeed in his role".

Pruitt's former deputy Andrew Wheeler has been put in temporary charge of the agency.

Trump has praised Pruitt for slashing regulations on the energy and manufacturing industries, including his move to repeal Democratic former President Barack Obama's signature program to cut carbon emissions from power plants, known as the Clean Power Plan. Among his other clients are the uranium mining company Energy Fuels Resources, the utility Xcel Energy, the biofuel firm Growth Energy, and the liquified natural gas company Bear Head LNG-all of which are regulated by the EPA.

Pruitt denied the allegations against him in April and has said little of the swirling scandals since then. Many within Pruitt's own agency had reportedly already turned against him and the White House press shop told the EPA to stop booking TV appearances for Pruitt, which he just started doing himself, current and former aides told the Post.

"It is extremely hard for me to cease serving you in this role first because I count it a blessing to be serving you in any capacity, but also, because of the transformative work that is occurring", Pruitt wrote.

The EPA was established in 1970 to protect human health and the environment.

Republicans say Wheeler is well-qualified to lead the EPA, having worked at the agency early in his career.

The problems will continue for both men: Pruitt still faces a dozen investigations and must file forms disclosing his income -and his wife's.

While Pruitt arrived in Washington as part of President Trump's promised wave of outsiders hoping to shake up the Capital, Wheeler has spent years navigating the intricacies of environmental policy. Mr. Pruitt was bad for the environment and bad for wildlife.

Wednesday night, Pruitt was on the White House lawn, watching fireworks explode over the Washington sky.

Wheeler was a lobbyist for Murray Energy, among the largest coal companies in the country. Inhofe expressed his support for his former staffer on Thursday, calling Wheeler "the ideal choice" to serve as acting EPA administrator. Documents later showed Pruitt's chief of staff had signed off on the pay hikes, indicating he had the administrator's consent.